JP2020514726A - Reactor system, transmitter device for the system, and related environmental condition measuring method - Google Patents

Abstract

The transmitter device (200, 300, 400, 500, 600) is a neutron detector (210, 610) configured to detect a neutron flux, and a capacitor (electrically connected in parallel to the neutron detector (210, 610) ( 212, 612), a gas discharge tube (214, 614) having an input end (216) and an output end (218), and an antenna (220, 320, 420, 520, 620) electrically connected to the output end (218). ) And. The input end (216) is electrically connected to the capacitors (212, 612). The antenna (220, 320, 420, 520, 620) is configured to emit a signal corresponding to the neutron flux.

Description

  The present invention relates generally to nuclear reactor systems. The invention also relates to a transmitter device for a nuclear reactor system. The invention further relates to a method of measuring an environmental condition using a transmitter device.

  Most modern nuclear reactor systems use in-core sensors that measure radioactivity in the core at various axial heights. These sensors are used to measure radial and axial power distribution in the core. Such power distribution measurement data is used to determine whether the reactor is operating within the limits of the reactor power distribution. A typical in-core sensor used to perform these functions is a self-powered detector that produces a current that is proportional to the amount of fission occurring in the environment. This type of sensor is commonly referred to as a self-powered detector, which does not require an external power source to generate an electric current, the details of which came into effect on April 28, 1998, It is described in US Pat. No. 5,745,538 assigned to the assignee of the invention. FIG. 1 is a diagram showing a mechanism for generating a current I (t) in a self-powered detector element 10. The emitter element 12 uses a neutron sensitive material such as vanadium and emits electrons in response to neutron irradiation. Self-powered detectors are typically packaged within an instrumentation thimble assembly. FIG. 2 shows a typical in-core instrumentation thimble assembly 16. The emitter element 12 shown in Figure 1 is essentially non-depleting, neutron sensitive and produces low signal levels. However, the neutron-sensitive emitter element, which extends the full length of the core, alone provides sufficient signal without complicated and expensive signal processors. The signal produced over the entire length of a single neutron-sensitive emitter element is the sum of the signal components, each originating from different axial regions of the core, each signal component defining the axial region of the core. , The signals generated by the gamma ray sensitive elements 14 having different lengths as shown in FIG. 2 are assigned to the respective axial regions. A ratio calculation on the allocated signals removes most of the effects of delayed gamma rays from fission products. The in-core instrumentation thimble assembly also includes a thermocouple 18 that measures the temperature of the coolant exiting the fuel assembly. The electrical signal outputs from the self-powered detector elements and thermocouples in each in-core instrumentation thimble assembly of the reactor core are collected in the electrical connector 20 and sent to a location at a sufficient distance from the reactor core. The final processing is performed and used to obtain the measured value of the power distribution.

  Figure 3 shows a fixed in-core instrumentation thimble within the core fuel assembly instrumentation thimble currently sold by Westinghouse Electric Company LLC, located in Cranberry County, Pennsylvania, under the product name WINCISE ™. An example of a core monitoring system for measuring the core power distribution using the assembly 16 is shown. A cable 22 originating from the instrumentation thimble assembly 16 extends through a containment seal pedestal 24 to a signal processing cabinet 26, where the output of the instrumentation thimble assembly is conditioned and digitized. After being multiplexed, it is routed through the containment wall 28 to a computer workstation 30 where it is further processed and displayed. The thermocouple signal from the in-core instrumentation thimble assembly is also sent to a reference junction device 32 which communicates with a plant computer 36 which is also connected to the workstation 30 to provide an inadequate core cooling monitor. A signal is transmitted to the core cooling monitor 34. Due to the harsh environment inside the containment wall 28, the signal processing cabinet 26 needs to be placed a significant distance from the reactor core, the signal of which leads to extremely expensive cables from the detector 16 to the signal processing cabinet 26. Need to send through. Since the cable is long, the signal-to-noise ratio is small. Unfortunately, such a long cable is required because the signal processing electronics must be shielded from the high radiation environment surrounding the core region.

  In a conventionally designed nuclear power plant, the in-reactor detector enters the reactor vessel from the hemispherical lower end and is inserted into the fuel assembly instrumentation thimble through the lower nozzle of the fuel assembly. At least some modern generation nuclear plants, such as the AP1000, have an inlet for in-core monitoring means at the top of the reactor vessel, which means that during refueling, all reactors are This means that it is necessary to remove the internal monitoring cable. If the in-reactor monitor built into the fuel assembly is a wireless type that sends a monitoring signal wirelessly to a receiver located at a position separated from the fuel in the reactor vessel, it is possible to immediately access the fuel. There is no need for the time-consuming and costly process of disconnecting, pulling out and storing in-core monitoring cables before accessing the assembly and reconnecting cables after the refueling process is complete. Therefore, the wireless method saves days of outage critical paths due to refueling. Also, since the wireless system allows monitoring of all fuel bundles, the amount of core power distribution information available is significantly increased.

  However, wireless systems require the placement of electronic components within or near the core where semiconductor electronic circuits are rendered inoperable in a very short time due to the presence of gamma rays, neutron rays and high temperatures. Vacuum tubes are known to be insensitive to radiation, but until recently, their size and current demand have hampered their use. Recent developments in microelectromechanical devices have allowed vacuum tubes to be scaled down to the size of integrated circuit components and to significantly reduce power consumption. Such a system is described in US patent application Ser. No. 12 / 986,242, entitled “Wireless In-core Neutron Monitor”, filed January 7, 2011. The primary source of signal transmission electrical hardware for the embodiments disclosed in that patent application is a rechargeable battery shown as part of an exemplary power source. The ultimate power source for this device is the radiation within the reactor, since the state of charge of the battery is maintained by the power generated by the dedicated power self-powered detector elements contained within the power source. This state of charge lasts as long as the dedicated self-powered detector element is exposed to intense radiation in the core.

  Accordingly, one of the objects of the present invention is to provide a mechanism for transmitting to remote locations data regarding environmental conditions within the instrumentation thimble of a fuel assembly.

  The above and other problems are solved by the present invention, which is directed to an improved reactor system, a transmitter apparatus for the system, and related methods of measuring multiple environmental conditions.

  In one aspect of the present invention, the transmitter device, a neutron detector configured to detect the neutron flux, a capacitor electrically connected in parallel to the neutron detector, a gas discharge tube having an input end and an output end, An antenna electrically connected to the output end. The input end is electrically connected to the capacitor. The antenna is configured to emit a signal corresponding to the neutron flux.

  In another aspect of the invention, there is provided a nuclear reactor system including a fuel assembly having an instrumentation thimble and the transmitter apparatus described above.

  In another aspect of the invention, there is provided a method of measuring a number of environmental conditions using the transmitter device described above. This method, the step of detecting the neutron flux with a neutron detector, the step of accumulating energy in the capacitor until reaching the breakdown voltage of the gas discharge tube, the step of transmitting a signal corresponding to the neutron flux from the antenna It is equipped with.

  The details of the present invention are explained below with reference to the accompanying drawings by taking preferred embodiments as examples.

It is a schematic diagram of a self-powered radiation detector.

It is a top view of an instrumentation thimble in a furnace.

FIG. 2B is a schematic diagram showing the inside of the front cylinder of the in-core instrumentation thimble assembly of FIG. 2A.

2B is a cross-sectional view of the electrical connector at the rear end of the in-core instrumentation thimble assembly of FIG. 2A. FIG.

It is a schematic layout of an in-reactor monitoring system.

1 is a simplified schematic diagram of a nuclear reactor system.

It is a partial cross-section elevation view of a reactor vessel and internal components.

FIG. 3 is a partial cross-sectional elevation view of a nuclear fuel assembly including an in-core nuclear instrumentation thimble assembly.

FIG. 3 is a schematic circuit diagram of a transmitter device according to one non-limiting embodiment of the present invention.

8 is a graph showing a voltage transition with time at a certain point on the circuit diagram of the transmitter device shown in FIG. 7.

8 is a graph showing a voltage transition with time at another point on the circuit diagram of the transmitter device shown in FIG. 7.

FIG. 6 is a schematic circuit diagram of another transmitter device in another non-limiting embodiment of the invention.

FIG. 6 is a schematic circuit diagram of another transmitter device in another non-limiting embodiment of the invention.

FIG. 6 is a schematic circuit diagram of another transmitter device in another non-limiting embodiment of the invention.

FIG. 6 is a schematic circuit diagram of another transmitter device in another non-limiting embodiment of the invention.

  The primary side of a nuclear power generation system that is cooled by pressurized water constitutes a closed circuit that is isolated from the secondary side for generating useful energy but is in heat exchange relationship with the secondary side. The primary side is a reactor vessel that houses a plurality of fuel assemblies containing fissile material and a core internal structure that supports the fuel assemblies, a primary circuit in a heat exchange steam generator, an internal space of a pressurizer, and pressurized water. A pump and piping for circulating the steam generator and the piping for connecting the steam generator and the pump to the reactor vessel independently. Each part on the primary side consisting of each set of a steam generator, a pump and a piping system connected to a reactor vessel forms a primary side loop.

  For purposes of illustration, FIG. 4 shows a simplified reactor system having a generally cylindrical pressure vessel 40 with a lid 42 enclosing a core 44. A reactor coolant such as water is pressed into a vessel 40 by a pump 46, absorbs thermal energy when passing through a core 44, and is sent to a heat exchanger 48 generally called a steam generator. The thermal energy is carried to a utilization circuit (not shown) such as a steam driven turbine generator. The reactor coolant is then returned to pump 46, completing the primary loop. Generally, multiple loops as described above are connected to a single reactor vessel 40 via reactor coolant piping 50.

FIG. 5 shows a design example of a nuclear reactor to which the present invention can be applied. The core 44 is composed of a plurality of fuel assemblies 80 that are parallel to each other and extend vertically. For the purpose of explanation, the other internal container structures are divided into a lower internal structure 52 and an upper internal structure 54. You can Conventionally designed lower core internals have the functions of supporting, aligning and guiding core components and instrumentation, as well as directing the flow of coolant within the vessel. The upper reactor internals 54 constrain the fuel assemblies 80 (only two shown for simplicity) or provide secondary restraining means to the fuel assemblies, such as instrumentation and control rods 56. Support and guide various components. In the case of the reactor illustrated in FIG. 5, the coolant flows into the reactor vessel 40 through one or more inlet nozzles 58, and the annular portion defined between the reactor vessel 40 and the reactor core 60. Flow through the lower reactor vessel plenum 61, and then flow through the lower core plate 64 on which the lower support plate and the fuel assembly 80 are seated upward, and flow in and around the assembly. Instead of the lower support plate 62 and the lower core plate 64, there is also a design in which a single structure lower core support plate is arranged at the same height as 62. The coolant that has left the core 44 flows under the lower surface of the upper core plate 66, and further flows upward through a plurality of holes 68 formed in the upper core plate 66. The coolant then flows upwardly and radially to one or more outlet nozzles 70.

  The upper furnace internal structure 54 can be attached to and supported by the container or the container lid 42, and the upper support assembly 72 is a part thereof. The load is transferred between the upper support assembly 72 and the upper core plate 66 mainly by the plurality of columns 74. Each strut is in alignment above a given fuel assembly 80 and a hole 68 in the upper core plate 66.

  The linearly displaceable control rod 56 generally includes a drive shaft 76 and a neutron poison rod spider assembly 78 which pass through the upper internals 54 by control rod guide tubes 79 and are in alignment. Guided into the fuel assembly 80.

  FIG. 6 is an elevational view of a fuel assembly, generally designated by the reference numeral 80, in a vertically shortened form. The fuel assembly 80 is of a type used in a pressurized water reactor as shown in FIG. 5, and has a structural body having a lower nozzle 82 at the lower end. The lower nozzle 82 supports the fuel assembly on the lower core support plate 64 in the reactor core region. The structural body of the fuel assembly 80 has, in addition to the lower nozzle 82, an upper nozzle 84 at the upper end and a number of guide tubes or thimbles 86. These guide tubes extend vertically between the lower nozzle 82 and the upper nozzle 84, and both ends are rigidly fixed to the nozzles.

  The fuel assembly 80 further includes a plurality of lateral grids 88 mounted at axially spaced positions on a guide thimble 86 (also referred to as a guide tube), and elongated fuel rods 90 supported laterally spaced by the grids 88. And an aligned array of. Not seen in FIG. 6, the conventional grid 88 consists of orthogonal straps interleaved to form an egg box pattern with the adjacent interfaces of the four straps defining a generally square support cell. The fuel rods 90 pass through the support cells and are supported in laterally spaced relation to each other. As with many conventional designs, springs and dimples are stamped into the opposing walls of the straps forming the support cells. The springs and dimples extend radially into the support cells to trap the fuel rods therebetween and press the fuel rod cladding to hold the fuel rods in place. Further, at the center of the fuel assembly 80, a measuring pipe 92 extending between the lower nozzle 82 and the upper nozzle 84 and attached to them is arranged. With this arrangement of parts, the fuel assembly 80 forms an integral unit that can be easily handled without compromising the overall structure of the parts.

  As described above, the array-shaped fuel rods 90 of the fuel assembly 80 are held in a mutually separated relationship by the grids 88 that are separated in the length direction of the fuel assembly. Each fuel rod 90 has a plurality of nuclear fuel pellets 94, both ends of which are closed by an upper end plug 96 and a lower end plug 98. The fuel pellet 94 is held in its stacked form by a plenum spring 100 located between the upper end plug 96 and the top of the stacked pellets. The fuel pellet 94 made of fissile material is the source of the nuclear reaction of the nuclear reactor. The coating surrounding the pellets acts as a barrier to prevent fission products from entering the coolant and contaminating the reactor system.

  To control the fission process, a plurality of control rods 56 are reciprocally movable within a guide thimble 86 in place on the fuel assembly 80. Specifically, the control rod 56 is supported by a rod cluster control mechanism (also called a spider assembly) 78 arranged above the upper nozzle 84. The rod cluster control mechanism has a cylindrical hub member 102 having a threaded interior and a plurality of arms 104 extending radially, which together with the control rod 56 form the spider assembly 78 described above with respect to FIG. .. Each arm 104 is interconnected to the control rod 56 so that when the control rod drive shaft 76 (shown in FIG. 5) coupled to the control rod hub 102 is driven by a motor, the control rod mechanism 78 is all known. In this manner, the control rods are moved vertically within the guide thimble to control the fission process within the fuel assembly 80.

  FIG. 7 shows a schematic circuit diagram of a transmitter device 200 in one non-limiting embodiment of the present invention. This exemplary transmitter device 200 is preferably installed in a thimble of one of the fuel assembly instrumentation thimbles 86 of FIG. As described in more detail below, transmitter device 200 enables wireless monitoring of environmental conditions (neutron flux as a non-limiting example) within instrumentation thimble 86 (FIG. 6).

  The exemplary transmitter device 200 includes a self-powered neutron detector 210, a first capacitor 212 electrically connected in parallel to the neutron detector 210, a gas discharge tube 214, an antenna 220, and an oscillator circuit 222. .. One example of a suitable gas discharge tube that may be used in the present invention is the product "Gas Discharge Tube", currently marketed by Little Hughes, Inc., Chicago, IL. The gas discharge tube 214 has an input end 216 and an output end 218. In one embodiment, the gas discharge tube 214 is designed as a spark gap device that produces an arc or spark when the input end 216 and the output end 218 conduct. In another embodiment, the gas discharge tube 214 is designed to generate a relatively low intensity glow discharge when the input end 216 and the output end 218 conduct. The input end 216 is electrically connected to the first capacitor 212, and the output end 218 is electrically connected to the antenna 220. As shown, the oscillator circuit 222 includes a second capacitor 224 and an inductor 226 electrically connected in parallel to the second capacitor 224. The second capacitor 224 and the inductor 226 are electrically connected to the output end 218 and the antenna 220, respectively.

  In operation, when transmitter device 200 is within one thimble of instrumentation thimble 86 (FIG. 6), neutron detector 210 absorbs neutrons and causes electrons to move outwards, resulting in a current. .. Therefore, the neutron detector 210, that is, the transmitter device 200 has an advantage of being self-powered (that is, not including a separate power supply mechanism). When the neutron detector 210 produces a current, this current charges the first capacitor 212.

FIG. 8 is a graph showing the time transition of the voltage V ₁ measured at the first capacitor 212. As shown, the voltage V ₁ increases until it reaches the voltage V _b . The voltage V _b is the breakdown voltage of the gas discharge tube 214. When the dielectric breakdown voltage V _b is reached, the gas discharge tube 214 becomes conductive, so that the input end 216 and the output end 218 electrically connect the first capacitor 212 to the antenna 220 and the oscillation circuit 222. The oscillator circuit 222 is an essentially unstable circuit. As shown on the left, when the breakdown voltage V _b is reached, strong oscillation occurs in the oscillation circuit 222 for a short period of time.

FIG. 9 is a graph showing the time transition of the voltage V ₂ measured by the oscillation circuit 222. As shown in the figure, the voltage V ₂ is generally zero volt before oscillation, oscillates for a relatively short period of time, then returns to zero volt, and this process is repeated cyclically. The vibration is attenuated due to the dissipation of energy due to the electromagnetic wave radiation from the antenna 220 and the resistance loss. Therefore, the antenna 220 transmits a radio signal by pulse power feeding from the oscillation circuit 222.

It can be seen that the cycle of the pulse signal transmitted from the antenna 220 is inversely proportional to the neutron flux detected by the neutron detector 210. Specifically, the current generated by the neutron detector 210 is directly proportional to the neutron flux in the instrumentation thimble 86 (FIG. 6) and the breakdown voltage V _b is relatively constant. As such, the pulse period (see, eg, t ₁ in FIG. 9) is also inversely proportional to the neutron flux in the instrument thimble 86 (FIG. 6). Therefore, the neutron flux in the instrumentation thimble 86 (FIG. 6) can be easily determined by calibrating an appropriate radio receiver that receives the transmission signal from the antenna 220. Further, even when the core power is very low, the energy of the pulse radiated from the antenna 220 is substantially unchanged, and the frequency of pulse generation only decreases. Furthermore, the frequency of the transmitter device 200 is independent of the pulse operation, so that the device designer can select the frequency of the transmitter device 200. This has the advantage that a number of different transmitter devices can be used at various locations within the fuel assembly 80 and other fuel assemblies within the core. The operator can identify an individual transmitter device by its frequency, which is determined by the capacitance of the second capacitor 224 and the inductance of the inductor 226. Therefore, there is an advantage that environmental conditions such as neutron flux can be wirelessly monitored at various places in the fuel assembly 80.

  FIG. 10 is a schematic circuit diagram of another transmitter device 300 in another non-limiting embodiment of the invention. As shown, the transmitter device 300 is similar in configuration to the transmitter device 200 (FIG. 7) and like components are labeled with like reference numerals. For simplification of the description and simplification of the disclosure, reference numbers are given only to the antenna 320 and the oscillation circuit 322. However, the oscillator circuit 322 of the transmitter device 300 also includes a resistance temperature detector 328 electrically connected in series to the inductor 326, as shown, which detector 328 is electrically connected to the second capacitor 324. There is. The electrical resistance of the resistance temperature detector 328 increases as the temperature of the environment in which it is placed rises. According to one aspect of the invention, resistance temperature detector 328 changes the signal emitted from antenna 320, which change is detectable. Specifically, by incorporating the resistance temperature detector 322, the voltage amplitude attenuation rate of the oscillation circuit 322 is changed. Therefore, by measuring the change in amplitude decay rate with a suitable radio receiver, the operator can easily determine a given temperature at some location within the instrumentation thimble 86 (FIG. 6). Therefore, the transmitter device 300, together with the neutron flux in the instrumentation thimble 86 (FIG. 6) (that is, obtained in the same manner as the transmitter device 200 shown in FIG. 7), displays the displayed value of the temperature in the thimble. There are advantages that can be provided to

  11 and 12 are schematic circuit diagrams of another two transmitter devices 400, 500, respectively, according to another non-limiting embodiment of the present invention. As shown, the transmitter devices 400, 500 are similar in construction to the transmitter devices 200, 300 (FIGS. 7, 10), and like components are labeled with like reference numerals. Only the antenna 420 and the oscillator circuits 422, 522 are numbered for simplicity and ease of disclosure. As shown in FIG. 11, the oscillator circuit 422 further includes a second inductor (a variable inductor 430 as a non-limiting example) electrically connected in series to the first inductor 426 and the resistance temperature detector 428. The variable inductor 430 is further electrically connected to the second capacitor 424. As shown in FIG. 12, the oscillator circuit 522 further includes a variable capacitor 532 electrically connected in parallel to the second capacitor 524. The variable capacitor 532 is also electrically connected to the inductor 526 and the resistance temperature detector 528. As an advantage, if there is a change in the electric value of the variable inductor 430 or the variable capacitor 532 due to environmental factors, a detectable change in the pulse transmission frequency occurs.

  It will be appreciated that the transmitter devices 400, 500 have the advantage of being able to provide the operator with display values for up to three environmental conditions within the instrumentation thimble 86 (FIG. 6). For example, each of the transmitter devices 400, 500, as well as the transmitter device 300 described above, via the signals emitted from the antennas 420, 520, to the neutron flux and temperature within the instrumentation thimble 86 (FIG. 6). Corresponding data can be sent to the wireless receiver. Furthermore, both variable inductor 430 (FIG. 11) and variable capacitor 532 (FIG. 12) are configured to cause a detectable change in the frequency of the signals emitted from their respective antennas 420, 520. The changed frequency is measured by a transmitter device 400, 500 measuring a third environmental condition (as a non-limiting example, pressure, total neutron dose of the fuel rod over time, flow rate of water, etc.) and a suitable receiver Provide a mechanism to allow wireless notifications to. For example, the pressure is wirelessly monitored by utilizing the fact that the fuel rod is deformed by the internal pressure and moves to the vicinity of the coil of the variable inductor 430 to cause a detectable change in the frequency of the signal transmitted from the antenna 420. can do.

  FIG. 13 is a schematic circuit diagram of another transmitter device 600 in another non-limiting implementation of the invention. As shown, the transmitter device 600 is similar in configuration to the transmitter devices 200, 300, 400, 500 (FIGS. 7, 10, 11, 12), and like components are labeled with like reference numerals. There is. Specifically, the transmitter device 600 includes a neutron detector 610, a capacitor 612, a gas discharge tube 614, an antenna 620, and an oscillator circuit 622, which are respectively transmitter devices 200, 300, 400, 500 (FIG. 7, 10, 11, 12) and perform the same function as the corresponding components. As illustrated, the transmitter device 600 further includes a multi-stage Marx circuit electrically connected between the neutron detector 610 and the gas discharge tube 614 (two-stage Marx circuits 642 and 644 are illustrated). It is understood that it is possible to place a Marx circuit of any number of stages in front of the gas discharge tube (that is, after the neutron detector) to exert the desired function of enhancing the circuit performance. Each stage of the Marx circuit 642, 644 includes a capacitor 646, 648, a first resistor 650, 652, a second resistor 654, 656, and a respective gas discharge tube 658, 660, respectively.

The method of measuring a number of environmental conditions with transmitter devices 200, 300, 400, 500, 600 includes detecting neutron flux with neutron detectors 210, 610 and breakdown voltage V _b of gas discharge tubes 214, 614. It can be seen that it comprises the steps of storing energy in the capacitors 212, 612 until reaching the point s, and transmitting a signal corresponding to the neutron flux by the antennas 220, 320, 420, 520, 620. This method further includes the step of pulse-feeding the antennas 220, 320, 420, 520, 620 from the oscillator circuits 222, 322, 422, 522, 622, and the transmission signals from the antennas 220, 320, 420, 520, 620 by resistance temperature. It may consist of varying with detectors 328, 428, 528 and / or varying the emitted signal from antennas 220, 320, 420, 520, 620 with variable inductor 430 or variable capacitor 532.

  The novel transmitter devices 200, 300, 400, 500, 600 of the present application measure the aforementioned environmental conditions within the instrumentation thimble 86 (FIG. 6) and are subjected to relatively severe operating conditions for at least two reasons. Can bear. As a first advantage, none of the transmitter devices 200, 300, 400, 500, 600 are semiconductor-free. Second, the transmitter devices 200, 300, 400, 500, 600 generally have only one signal-powered mechanism (eg, each neutron detector (only the neutron detector 210, 610 is numbered). )). Conventional attempts to wirelessly transmit environmental data require more power than is typically available from neutron detectors, or the inbuilt semiconductors cannot withstand relatively harsh radiation environments. Or both. Also, some known devices (not shown) shut down completely when the reactor power falls below a critical threshold because the transmitter power is relatively low. The transmitter devices 200, 300, 400, 500, 600 combine the self-powered neutron detectors 210, 610 with the power storage capacitors 212, 612 to provide reasonable transmit power over a wide reactor power range. The point is novel. In addition, the transmitter devices 400, 500 have the advantage of being able to simultaneously transmit up to three different environmental parameter display values from a given sensing location within the instrumentation thimble 86, as described above. Moreover, since all monitoring is done wirelessly, the need to provide major reactor vessel penetrations and cables for environmental condition monitoring is reduced and / or eliminated.

  Accordingly, the present invention is directed to an improved reactor system (as a non-limiting example, a reactor system having an improved ability to monitor environmental conditions within the instrumentation thimble 86), and transmitter devices 200, 300 for the reactor system. , 400, 500, 600, and related methods for measuring environmental conditions.

Although particular embodiments of the present invention have been described in detail, those skilled in the art will be able to make various modifications and alterations to these detailed embodiments in light of the teachings throughout this disclosure. Accordingly, the particular arrangements disclosed herein are for illustration purposes only and do not limit the scope of the invention in any way, and the scope of the present invention is the full scope of the appended claims and all equivalents thereof. Including things.

Claims (15)

A transmitter device (200, 300, 400, 500, 600),
A neutron detector (210, 610) configured to detect neutron flux,
Capacitors (212, 612) electrically connected in parallel to the neutron detector (210, 610),
A gas discharge tube (214, 614) having an input end (216) and an output end (218), the input end (216) being electrically connected to the capacitor (212, 612);
A transmitter device comprising an antenna (220, 320, 420, 520, 620) electrically connected to the output end (218) and configured to emit a signal corresponding to the neutron flux.   An oscillation circuit (222, 322, 422, 522, 622) electrically connected to the output terminal (218) and the antenna (220, 320, 420, 520, 620) is further included, and the oscillation circuit (222, 322, 422, 522, 622) is configured to pulse power said antenna (220, 320, 420, 520, 620). Transmitter apparatus (200, 300, 400, 500, 600).   The oscillation circuit (222, 322, 422, 522, 622) is a second capacitor (224, 324, 424, 524) and an inductor electrically connected to the second capacitor (224, 324, 424, 524). (226, 326, 426, 526), and the second capacitors (224, 324, 424, 524) and the inductors (226, 326, 426, 526) are the antennas (220, 320, 420, respectively). Transmitter device (200, 300, 400, 500, 600) according to claim 2, characterized in that it is electrically connected to (520, 620).   The oscillation circuit (322, 422, 522) further includes resistance temperature detectors (328, 428, 528) electrically connected in series to the inductors (326, 426, 526), and the resistance temperature detector (328). , 428, 528) is configured to vary the signal emitted from the antenna. 4. Transmitter device (300, 400, 500) according to claim 3, wherein   The oscillator circuit (422) further includes a second inductor (430) electrically connected in series with the inductor (426), and the second inductor (430) changes a signal transmitted from the antenna. The transmitter device (400) of claim 3, wherein the transmitter device (400) is configured as follows.   The transmitter apparatus (400) of claim 5, wherein the second inductor (430) is a variable inductor (430).   The transmitter apparatus (600) of claim 2, further comprising a multi-stage Marx circuit (642, 644) electrically connected between the neutron detector (610) and the gas discharge tube (614).   The transmitter device (200, 300, 400, 500, 600) of claim 1, wherein the transmitter device (200, 300, 400, 500, 600) is semiconductor-free.   The transmitter device (200, 300, 400, 500, 600) has only one signal feeding mechanism, and the feeding mechanism is the neutron detector (210, 610). Item 1. The transmitter device (200, 300, 400, 500, 600). A nuclear reactor system,
A fuel assembly (80) comprising an instrumentation thimble (86),
A transmitter device (200, 300, 400, 500, 600),
The transmitter device is
A neutron detector (210, 610) disposed within the instrumentation thimble (86) and configured to detect neutron flux;
Capacitors (212, 612) electrically connected in parallel to the neutron detector (210, 610),
A gas discharge tube (214, 614) having an input end (216) and an output end (218), the input end (216) being electrically connected to the capacitor (212, 612);
A nuclear reactor system comprising an antenna (220, 320, 420, 520, 620) electrically connected to the output end (218) and configured to emit a signal corresponding to the neutron flux.   The transmitter device (200, 300, 400, 500, 600) has an oscillator circuit (222, 322, 422) electrically connected to the output terminal (218) and the antenna (220, 320, 420, 520, 620). 522, 622), and the oscillation circuit (222, 322, 422, 522, 622) is configured to pulse-feed the antenna (220, 320, 420, 520, 620). The nuclear reactor system of claim 10, wherein:   The oscillation circuit (222, 322, 422, 522, 622) is a second capacitor (224, 324, 424, 524) and an inductor electrically connected to the second capacitor (224, 324, 424, 524). (226, 326, 426, 526), and the second capacitors (224, 324, 424, 524) and the inductors (226, 326, 426, 526) respectively include the antennas (220, 320, 420). , 520, 620) electrically connected to the reactor system of claim 11. A method for measuring a number of environmental conditions by a transmitter device (200, 300, 400, 500, 600), wherein the transmitter device (200, 300, 400, 500, 600) is a neutron detector (210, 610), a capacitor (212, 612) electrically connected in parallel to the neutron detector (210, 610), a gas discharge tube (214, 614) having an input end (216) and an output end (218), and The method comprises an antenna (220, 320, 420, 520, 620) electrically connected to the output end (218), the input end (216) being electrically connected to the capacitor (212, 612), ,
Detecting a neutron flux by the neutron detector (210, 610),
Storing energy in the capacitors (212, 612) until the breakdown voltage of the gas discharge tubes (214, 614) is reached,
Emitting a signal corresponding to the neutron flux by the antenna (220, 320, 420, 520, 620). The transmitter device (200, 300, 400, 500, 600) has an oscillator circuit (222, 322, 422) electrically connected to the output terminal (218) and the antenna (220, 320, 420, 520, 620). 522, 622),
14. The method of claim 13, wherein the method further comprises the step of pulse powering the antenna (220, 320, 420, 520, 620) by the oscillator circuit (222, 322, 422, 522, 622). .. The oscillation circuit (322, 422, 522) includes a second capacitor (324, 424, 524), an inductor (326, 426, 526) electrically connected to the second capacitor (324, 424, 524), and A resistance temperature detector (328, 428, 528) electrically connected in series to the inductor (326, 426, 526), the second capacitor (324, 424, 524) and the inductor (326, 426, 526) are electrically connected to the antennas (320, 420, 520), respectively,
15. The method of claim 14, wherein the method further comprises the step of varying the signal emitted from the antenna (320, 420, 520) by the resistance temperature detector (328, 428, 528).